1. Technical Field
The present invention relates to a driving environment risk determination apparatus that determines from the situation of a vehicle equipped with the apparatus and another vehicle the degree of risk of an environment in which the vehicle equipped with the apparatus is running and relates to a driving environment risk notification apparatus.
2. Related Art
In order to improve traffic conditions and safety of vehicles such as automobiles, research and development of an Intelligent Transport System (ITS) has recently been underway for the sophistication of navigation systems, safe driving assistance, optimization of traffic management, and improvement to road management efficiency.
In addition, there has also been developed an Advanced Safety Vehicle (ASV) as an automobile compatible with the ITS that is equipped with various sensors and other information recognition systems for collecting various pieces of information about the surrounding driving environment and road conditions and the like and supports a driver's safe driving based on thus collected information and other recognition results.
In the field of ASVs, various technologies have been reviewed for driving assistance that uses road-to-vehicle communication between a base station installed on a road and a mobile station installed in a vehicle, vehicle-to-vehicle communication between mobiles stations, and other wireless communications. As information-exchange-type driving assistance technology, for instance, there have been proposed various technologies for extracting information about a vehicle that is highly likely to collide on the basis of received information about other vehicles and providing a driver of a vehicle equipped with such technology (hereinafter referred to as “subject vehicle”) with the information or alerting the driver to impending danger in order to prevent a vehicle crash.
For this type of driving assistance, as disclosed in, for instance, Japanese Unexamined Patent Application Publication (JP-A) No. 2008-65480, location information and the like about a subject vehicle and another vehicle (e.g., information about latitude, longitude, azimuth, and the like received through the GPS) is used to perform map-matching (mapping) with road network data from which relative positional relationship of the vehicles on the road is derived in order to determine the likelihood of colliding with the other vehicle.
Japanese Unexamined Patent Application Publication (JP-A) No. 2012-155535 discloses a driver status notification system provided with a notification unit that notifies the driver of the state of another vehicle. Specifically, with reference to FIGS. 1A and 1B and the description of the publication, such a system includes a subject vehicle location detection unit 15a that detects the location of the subject vehicle, a driver status acquisition unit 15b that acquires a driver status, and a communication unit 15c that communicates with the outside of the subject vehicle, while pieces of equipment installed outside the subject vehicle include a wireless station, a server that creates delivery data (delivery data creation unit), and a delivery unit that delivers delivery data to each vehicle. With this arrangement, the notification unit 15d notifies the driver of the information about the other vehicle located in the vicinity of the subject vehicle, thereby enabling the driver to drive the subject vehicle safely in accordance with the information about the status of the other vehicle.
Systems disclosed in JP-A No. 2008-65480 and JP-A No. 2012-155535 notify the driver of the subject vehicle of the state of another vehicle near the subject vehicle, thereby enhancing driving safety of the subject vehicle. However, not only the state of another vehicle but also the environment and other factors surrounding the subject vehicle may have a major impact on the safety of the subject vehicle.